What seismic measures and what we require for reservoir characterization the parameters measurable from the seismic data are 1 travel time, 2 amplitude, 3 the character of events, and. The amplitude variation with offset avo and pre stack inversion. Well data are gotten from rock samples and measurements at depth from a wellbore. Reflection seismic data from the f3 block in the dutch north sea exhibits many largeamplitude reflections at shallow horizons, typically categorized as brightspots schroot and schuttenhelm, 2003, mainly because of their bright appearance. Quantitative seismic interpretation demonstrates how rock physics can be applied to predict reservoir parameters, such as lithologies and pore fluids, from seismically derived attributes.
These rules of thumb help select the best seismic attribute for calibrating amplitude to rock properties in different areas. Waves transmitted at the ocean bottom have the characteristics that, for any incidence angle, the attenuation vector is perpendicular to the oceanbottom interface assuming water to be a lossless medium. However, in current seismic amplitude interpretation, displacement is the most frequently considered factor hilterman, 2001. Basics of seismic interpretation linkedin slideshare. Seismic data interpretation is a primary method of viewing and mapping subsurface geologic features, making interpretation of structure and stratigraphy possible away from well control.
Seismic rockproperty transforms for estimating lithology. Benefits and limitations of these attributes in soft to hardrock environments are discussed with model data and in case histories. Seismic amplitude interpretation 2001 segeage distinguished instructor short course by fred hilterman. Increase in impedance starts with high amplitude and reduces with offset class 2. To acquire skills in interpretation of 3d seismic data to enhance theoretical knowledge of seismic structural interpretation, stratigraphic interpretation, reservoir identification and evaluation, and horizon and formation attributes. During that time he has interpreted seismic data from various basins around the. Seismic amplitude interpretation, distinguished instructor. Seismic amplitudes yield key information on lithology and fluid fill, enabling interpretation of reservoir quality and likelihood of hydrocarbon presence.
From the worldwide exploration examples shown during this sixday conference, the answer could clearly be stated that avo was an integral part of recognizing and highgrading prospects and. The last part examines the numerous amplitude attributes that can be extracted from seismic to quantify an interpretation. Amplitude versus offset avo modelling and analysis for. Seismic amplitude interpretation distinguished instructor series.
At big sky, montana, in 1992, the segeaeg joint research committee held the summer workshop, how useful is amplitudeversusoffset avo analysis. Rearranged shueys equation to emphasize the rockproperty dependence on incident angle. Seismic interpreters can be geologists, geophysicists, and even engineers. Similar to a standard class 2 anomaly but a polarity reversal in the near offsets.
The single reflector shown will produce a seismic reflection caused by the contrast between the density. Seismic amplitude is an invaluable daytoday tool for graduate students and industry professionals in geology, geophysics, petrophysics, reservoir engineering, and all subsurface disciplines making regular use of seismic data. European association of geoscientists and engineers society of exploration geophysicists. During the last 30 years, seismic interpreters have routinely applied bright spot and avo. June 2005 seismic amplitude interpretation petrobras april 2005 seismic amplitude interpretation oxy 2005 seg seismic amplitude interpretation course. Seismic amplitude changes may tell us something about reservoir lithology, porosity, andor fluids. Seismic amplitude by rob simm cambridge university press. The authors provide an integrated methodology and practical tools for quantitative interpretation, uncertainty assessment, and characterization of subsurface. Pdf seismic amplitude download full pdf book download. Avo classes reference guide there is a second class 2 anomaly.
The fundamental parameters in seismic reservoir characterization are pwave, s wave velocities. Again, success depends on zerophase, trueamplitude seismic data. Seismic reflection an overview sciencedirect topics. Seismic amplitude calibration for quantitative interpretation. Extended elastic impedance eei has proved to be a highly convenient framework for. Well log interpretation and amplitude versus offset avo analysis 48. Examples of seismic attributes can include measured time, amplitude, frequency and attenuation, in addition to. Application of extended elastic impedance eei inversion. Bright spots were not commonly identified until the early 1970s because of the extensive and industrywide use of automatic gain control, which obscured the amplitude effects of hydrocarbon accumulations theory.
Impedance difference is minimal starts with a low amplitude and increases. However, seismic tuning effects are potentially much larger than amplitude variations due to geological changes. The seismic interpreter can interpret elastic inversion results without indepth knowledge about rock physics theory. Seismic interpretation is the thoughtful procedure of separating these effects. D colorado school ofmines, 19661970 uh appointments. Seismic amplitudeversus offset avo analysis has been a powerful geophysical method in. A bright spot primarily results from the increase in acoustic impedance contrast when a hydrocarbon with a lower acoustic impedance replaces the brinesaturated zone with. Formerly, a book, now available on cdrom, this title was written to be an introduction to the geologic interpretation of seismic data. Avo principles, processing and inversion crewes research report volume 18 2006 5 r. Tuning, avo, and flatspot effects in a seismic analysis. The fundamental seismic data type is amplitude data, but seismic attributes generated from amplitude can.
A case history illustrates the rockproperty calibrations that are needed. Our threeyear plan for the seismic quantification in reservoir delineation and characterization project is multifold with nine different areas of research. William abriel, john castagna, douglas foster, fred hilterman, ron masters, george smith, and chuan yin. This accessible, authoritative book provides a complete framework for seismic amplitude interpretation and analysis, guiding the interpreter through techniques with practical observations and helping to evaluate interpretation confidence independent of any commercial software products. Seismic interpretation philosophy 11 four steps of interpretation 12 expansion of interpretation objectives 12 ib. Each of these simplifications in a degree links reflection amplitude with. Seismic amplitude is an invaluable daytoday tool for graduate students and industry professionals in geology, geophysics, petrophysics, reservoir engineering, and all subsurface disciplines. Amplitude versus offset avo modelling and analysis for quantitative interpretation of. Pdf seismic amplitude calibration for quantitative.
Pdf 5 popular pitfalls in seismic amplitude interpretation. For conventional oil and as 3d seismic interpretation by bacon et al. Professor distinguished research professor of geophysics, reflection seismology. This accessible, authoritative book provides a complete framework for seismic amplitude interpretation and analysis in a practical manner that allows easy. Geo expro a simple guide to seismic amplitudes and detuning. Seismic interpretation an overview sciencedirect topics.
At uh, fred cofounded the seismic acoustics laboratory sal. Describe three potential erroneous interpretations associated with doing an amplitude interpretation using 2d seismic data. David lane1 abstract we investigate the effects of changes in rock and. Amplitude, frequency and bandwidth and their relationship. Application of relations between seismic amplitude. Quantitative seismic interpretation based on prestack seismic data, such as amplitude variation with offset avo analysis, allowing the extraction of geological features with greater accuracy.
Cambridge core solid earth geophysics seismic amplitude by rob simm. Understanding this key concept is critical to effective seismic interpretation. Interpretation of rock physics template the rock physics template is based on a compiled catalog or atlas of rpts calculated by a rock physics expert. A seismic interpretation study should access the following data sets 2d or 3d seismic data cube.
Advanced seismic interpretation is a course designed for graduate students. The last part examines the numerous amplitude attributes that can be extracted from seismic to. Interpretation of dhi characteristics with machine learning. Amplitude, frequency and bandwidth and their relationship to. Consider the effect of wavelet shape on the geologic interpretation of seismic response.
Seismic quantification in reservoir delineation and. To be effective, it is necessary to teach geologists and engineers a bit of geophysics, and geophysicists and engineers a bit of. In most cases, these bright reflections show a significant flatness contrasting with local structural trends. Quantitative use of seismic attributes for reservoir. In reflection seismology, a seismic attribute is a quantity extracted or derived from seismic data that can be analysed in order to enhance information that might be more subtle in a traditional seismic image, leading to a better geological or geophysical interpretation of the data. The seismic wavelet starts as the pulse of seismic energy, which, generated by the energy source, travels down through the earth, is reflected and travels back up to the surface receivers carrying the geological information with it.
Application of relations between seismic amplitude, velocity and lithology in geological interpretation of seismic data smiljan prskalo1 1ina d. During the last 30 years, seismic interpreters have routinely applied bright spot and avo technology for recognizing prospects and predicting lithology. The last part examines the numerous amplitude attributes that can be extracted from seismic data to quantify an interpretation. Integral formulation for migration in two and three dimensions. Well data required for interpretation are wireline logs gamma ray logs, resistivity logs, porosity log, sonic logs, density logs and neutron logs or equivalent rock property model, check shot data.